1. Field of the Invention
The present invention relates to a measuring device, especially to a plumb probe assembly for a measuring device that detects heights of particulates added to a container.
2. Description of the Prior Arts
Particulates including, but not limited to animal feeds, cements, plastic grains or corns comprising grains, lumps and powders are stored in containers. The container has a top, a bottom, a level measuring device and a particulate discharging device. The level measuring device is mounted on the top of the container to detect a fill level of the particulates and has a controlling assembly and a conventional plumb probe assembly. The controlling assembly has a spool, a line and a motor. The line is wound around the spool and has a distal end. The motor connects to and rotates the spool to allow the spool to selectively wind or unwind the line. The conventional plumb probe assembly is metal and connects to the distal end of the line. The particulate discharging device is mounted on the bottom of the container, stirs and discharges the particulates in the container.
When the conventional plumb probe assembly is lowered into the container and is in contact with a top of the particulates, the conventional plumb probe assembly is partially supported by the particulates and the controlling assembly detects a reduction in tensile force imposed on the line. Therefore, the motor winds the spool, to raise the conventional plumb probe assembly until the controlling assembly detects the tensile force imposed on the line returns to equal the weight of the conventional plumb probe assembly. Accordingly, the fill level of the particulates in the container is known.
However, if the conventional plumb probe assembly is buried by particulates in the container, the motor might overload the line, causing the conventional plumb probe assembly to break off or a weight of the particulates becomes larger than the pulling force of the motor, the line cannot be wound, both effectively turning the particulate discharging device into a permanent on state. Alternatively, stirrers of the particulate discharging device might engage the conventional plumb probe assembly or line, pulling the line and causing damage to the particulate discharging device or tangling the line on the stirrer and turning the particulate discharging device permanently on. Finally, the particulate discharging device can only add particulates to the container and cannot remove particulates from the container. Therefore, any above situation would cause overfilling, leading to a waste of particulates, an increase in cleaning costs and could lead to reduced production or even factory closure.
To overcome the shortcomings, the present invention provides a plumb probe assembly for a level measuring device to mitigate or obviate the aforementioned problems.